【opencart3源码分析】postgresql类pgsql.php

<?php
namespace DB;
final class PgSQL {
  private $connection;

  // 构造方法
  public function __construct($hostname, $username, $password, $database, $port = '5432') {
    $this->connection = @pg_connect('hostname=' . $hostname . ' port=' . $port .  ' username=' . $username . ' password=' . $password . ' database=' . $database);

    if (!$this->connection) {
      throw new \Exception('Error: Could not make a database link using ' . $username . '@' . $hostname);
    }

    pg_query($this->connection, "SET CLIENT_ENCODING TO 'UTF8'");
  }

  // 查询
  public function query($sql) {
    $resource = pg_query($this->connection, $sql);

    if ($resource) {
      if (is_resource($resource)) {
        $i = 0;

        $data = array();

        while ($result = pg_fetch_assoc($resource)) {
          $data[$i] = $result;

          $i++;
        }

        pg_free_result($resource);

        $query = new \stdClass();
        $query->row = isset($data[0]) ? $data[0] : array();
        $query->rows = $data;
        $query->num_rows = $i;

        unset($data);

        return $query;
      } else {
        return true;
      }
    } else {
      throw new \Exception('Error: ' . pg_result_error($this->connection) . '<br />' . $sql);
    }
  }

  // 过滤
  public function escape($value) {
    return pg_escape_string($this->connection, $value);
  }

  // 受影响行数
  public function countAffected() {
    return pg_affected_rows($this->connection);
  }

  //判断是否已经连接
  public function isConnected() {
    if (pg_connection_status($this->connection) == PGSQL_CONNECTION_OK) {
      return true;
    } else {
      return false;
    }
  }

  // 获取最后一条记录id
  public function getLastId() {
    $query = $this->query("SELECT LASTVAL() AS `id`");

    return $query->row['id'];
  }

  // 关闭连接
  public function __destruct() {
    if ($this->isConnected()) {
      pg_close($this->connection);
    }
  }
}